The pair of images, captured amid the melee that erupted inside the U.S. Capitol last week, are difficult to look at, but not hard to interpret.

One photo, shot overhead from the portico, shows a frenzied mob of extremists who support President Donald Trump – wearing Make America Great Again gear or sporting paraphernalia such as yellow Gadsden flags – swarming a uniformed Capitol Hill police officer attempting to guard the building. As some in the mob tried to drag him down steps of the portico, others clubbed him with various objects, including a metal crutch.

The other image shows another Capitol Police officer mingling with a group of rioters standing amid debris in a lobby. Instead of arresting the invaders, he posed with them for a selfie.

The sharp contrast of an officer hanging with members of the same far-right mob that is attacking his comrade stunned observers, raising questions about whether the rioters had allies in police uniforms. But Seth Jones wasn't surprised: The same problem he's seen in Germany's police departments has been exposed as an issue in American law enforcement.

"One of the most significant German problems has been the prevalence of these extremist views" among members sworn to uphold the law and protect the public, says Jones, a senior global security analyst for the Center for Strategic and International Studies. "What's not clear at the moment is to what degree there are similarities and how prevalent" they are.

For decades, authorities in Berlin and other German cities have struggled to root out elements of the far right in law enforcement, including supporters of various white-power movements. Last year alone, investigators staged raids on the homes of police officers across the country, seizing dozens of weapons, confiscating illegal Nazi literature and foiling at least one apparent assassination plot against a local politician.

Yet the movement to eradicate secret white supremacist movements within the law-enforcement ranks has become a high-stakes game of Whack-a-Mole for German authorities: Every cell upended or plot foiled is often quickly replaced by another underground network of officers who, analysts say, hate immigrants, minorities and the government they believe coddles them at the expense of "true Germans."

The death of George Floyd, an African American man who died at the hands of Minneapolis police in May 2020, ignited a summer of nationwide protests in the United States against police use of deadly force against African Americans and exported the Black Lives Matter movement worldwide. Yet experts who study extremism in law enforcement say the U.S., like Germany, has long ignored racist extremism in police departments, blaming the deadly force problem on "a few bad apples."

But the Jan. 6 riots at the Capitol, in which some of the off-duty officers reportedly flashed their badges, carried firearms and wore body armor, has brought the problem into sharp relief.

Men and women sworn to uphold the law, yet participating in an armed, violent insurrection raises thorny questions about how deeply far-right elements have penetrated U.S. law enforcement, and whether Germany can provide useful lessons in uprooting it.

"I spent a lot of time believing that the reason why there was so much racism and hatred in our country was because we never faced our racist history," says Vida Johnson, a Georgetown University law professor who studies extremism in U.S. law enforcement. Yet Germany has atoned for the rise of Nazis and the Holocaust, children learn the unsparing lessons about the war and the government has taken steps to prevent a reoccurrence, including banning far-right political parties and Nazi symbols; the country's "Volksverhetzung," (incitement to hatred) laws criminalize hate speech.

"In Germany, every kid at every grade level, elementary school and high school – they talk about the Holocaust and about hatred, and there's markers to the Holocaust throughout the country," says Johnson. "Yet they have a significant problem with racism now. That, to me, is really scary."

In the U.S., numbers compiled after the riot tell part of the story.

The Appeal, an investigative journalism website, compiled a spreadsheet of law enforcement officers who were involved in the Capitol Hill riot. The data shows that 31 law enforcement officers from more than a dozen states -- including California sheriff's deputies, detectives from big-city departments such as New York's and a police chief from small-town New England -- are under arrest, under investigation or implicated in the Capitol Hill riot.

But that number doesn't include the Capitol Police, where at least two officers have been suspended and several more are under investigation for their actions that day.

In her research, Johnson found that since 1990 there have been at least 100 racist incidents involving police in more than 40 different states. The offenses range from officers sending bigoted emails or text messages to making offensive remarks on social media.

And a report from the Brennan Center, a public policy think tank based at New York University, found that departments atoning for high-profile incidents of racist misconduct or brutality usually accept or ignore explicitly racist activity among the rank and file, such as membership in the League of the South or the KKK.

After turning a blind eye to the problem for decades, authorities in Germany have launched a campaign against racist elements from police departments at the local, state and federal levels. Yet while America and Germany share the same difficult issue, their approaches to it are sharply different.

Jones, the CSIS expert, says Germany has tried to tackle the problem head on, raiding officers' homes and aggressively disruptingnetworks. Authorities issue periodic reports analyzing the problem, and the government has banned extremist political parties like Sturmbrigade 44, which promoted reestablishment of the Nazi state.

By contrast, Jones says, there has been next to no official analysis of extremism in U.S. law enforcement, Nazi symbols are considered freedom of expression and any attempt to ban extremist groups would likely end with a First Amendment lawsuit.

Still, even with laws banning hate speech and Nazi regalia, Germany has struggled to control the spread of extremism among police. Last year alone, authorities broke up several right-wing networks, including a group calling itself Northern Cross.

Self-styled commandos who met in a private online chat group, Northern Cross members amassed an arsenal of weapons, tens of thousands of rounds of ammunition, body bags and enough food rations for short-term survival off the grid. Led by an active-duty police officer who was also a trained sniper, the group accumulated supplies through like-minded connections in the German army.

Their alleged plot -- kidnap or kill politicians they believe indulge minorities and immigrants but ignore hard-working white people like them -- was thwarted when police raided homes of Northern Cross members. Besides the weapons and ammo, authorities found a sketch of the home of a local politician on their hit list; he'd allowed two police officers to draw it when they told him they were investigating death threats against him.

Both Jones and Johnson, the Georgetown professor, believe that the pro-Trump riot at Congress underscores that the government must act with urgency to eliminate white supremacists from a profession that is supposed to protect and serve the public, including people of color.

To break up the networks, Jones says, local and national authorities like the FBI should take a few lessons from Germany: Determine the extent of the problem and how it manifests itself in law enforcement operations.

"One of the biggest issues I've had in the U.S., even over the last year, is how little information the U.S. government has provided publicly about the state of the threat - the number of plots, the number of attacks," Jones says. "The FBI doesn't generally provide public information or even numbers. And when the (Department of Homeland Security) provides it, it's generally slightly old."

Jones says it was no coincidence so many off-duty officers are being swept up in post-riot arrests; indeed, she says, it could explain why police use a heavy hand with Black Lives Matter protesters but look past a threat in plain view.

They apparently couldn't imagine the danger of a pro-Trump rally of people "who had Blue Lives Matter flags, and look like people in their family," she says.

Jones and Johnson agree that job one is to summon the political will for an accurate, detailed assessment of far-right organizations in law enforcement, starting with the Capitol Police. Next up: Sweeping reforms, including overhauling laws and labor contracts that keep rogue officers on the job.

"It's very difficult to fire officers in most jurisdictions because of the power that police unions have," Jones says. For years, she says, municipalities have given in to union demands that set high standards for termination; as a result, "you've got officers who murder people who still end up on the force after years of appeals."

Until that changes, she says, nothing will.